The present patent application relates to locking mechanisms, and, more particularly, to polyaxial locking mechanisms for surgical components such as bone plates.
In certain orthopedic surgical procedures, it is necessary to secure multiple bones or bone portions relative to each other. For example, in wrist or ankle surgeries, the joining of two or more bone portions or fragments may be required to promote healing and restore function. The need for such procedures may be the result of physical trauma from fractures or dislocations, degenerative diseases, or the like.
Various types of bone plate systems can be used for internal fixation of bones. Exemplary bone plate systems can include a bone plate that is configured to be attached to one or more bone portions spanning a fracture line. The bone plate generally includes a plurality of apertures through which bone screws and/or bone pegs are inserted for engaging the bone. In an example, the bone plate systems can include locking screws, which can be adapted for locking in corresponding plate apertures in a fixed orientation. An advantage of “locked plating” systems is that they do not require the bone plate to be compressed to the bone. Rather, the interface formed between the bone plate and the locking screws can eliminate the need for compression between the plate and the bone. In another example, the bone plate systems can include non-locking screws, which can be configured for insertion at an orientation selected by the user. Unlike “locked plating” systems, “non-locked plating” systems rely on the friction formed between the bone plate and the bone when the screw is inserted through the bone plate and tightened.
Although numerous bone plate systems exist for use in orthopedic surgical procedures, there is still a need for improved bone plate systems that provide the locking characteristics associated with traditional locking screws as well as the variable screw orientation associated with traditional non-locking screws.